1. Field of the Invention
This invention relates generally to a forward collision warning system for a vehicle and, more particularly, to an algorithm for determining a driver alert level for a forward collision radar warning system associated with a vehicle.
2. Discussion of the Related Art
Various types of safety systems are known in the art for protecting the occupants of a vehicle in the event of a collision. Some of these systems attempt to prevent the collision before it occurs. For example, it is known to equip a vehicle with a forward looking collision warning laser or radar system that alerts the driver of a potential collision with objects, such as other vehicles, in the vehicle""s path to allow the driver to take corrective measures to prevent the collision. The collision warning system transmits a radar or laser beam forward of the vehicle and processes reflections from objects in the path of the vehicle. The system generates measurements from the reflections and assesses the potential for a collision based on the vehicle speed and direction relative to the objects. The alert can be a visual indication on the vehicle""s instrument panel or in a head-up display (HUD), and/or can be an audio warning or other HAPTIC feedback device. Examples of vehicle collision warning systems of this type can be found in U.S. Pat. Nos. 6,275,180; 6,097,311 and 5,979,586.
In accordance with the teachings of the present invention, an algorithm for use in connection with a forward looking collision warning system employed in a vehicle is disclosed. The collision warning system includes a radar or laser device that generates track files of the range and closing rate of objects in the path of the vehicle. The system also includes a collision warning processor running the algorithm that receives the track files and various input data to determine whether an alert of an impending collision with one or more of the objects should be issued, and if so, to what degree. The input data includes vehicle dynamics inputs, such as the speed and acceleration of the vehicle, whether the vehicle brakes are being applied, the vehicle gear, the vehicle yaw rate, etc. The input data also includes driver inputs, such as collision warning sensitivity, driver distraction modifiers, etc. Additionally, input data for road conditions, such as wiper speed and outside air temperature, is provided to the processor. The processor calculates an alert level based on the various inputs, and outputs the alert level to a driver vehicle interface to notify the driver of a potential collision. The system also determines whether an adaptive cruise control has been activated, and if so, automatically makes vehicle corrections to prevent a collision.
Additional objects, advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.